Improvement Of Pretreatment Technology And Facilities Of Emulsion Wastewater From Mechanical Processing

Emulsion wastewater produced by mechanical processing industry has the characteristics of high concentration of pollutants,difficult treatment and high treatment cost.The conventional treatment method is to discharge it into the comprehensive sewage treatment plant for further treatment after pretreatment.At present,the pretreatment process and facilities of emulsion wastewater from mechanical processing are imperfect,and the treated emulsion wastewater cannot reach the influent standard of municipal comprehensive wastewater treatment plant.It produces serious impact on the normal operation of wastewater treatment plant,and further restricts the development of mechanical processing industry.To ensure the stable development of the mechanical processing industry and the normal operation of the sewage treatment plant,it is urgent to study the pretreatment process and facilities which can rapidly degrade pollutants in emulsion wastewater.Taking an emulsion wastewater pretreatment center in Taizhou as an example,this paper studies the improvement scheme of pretreatment process and facilities for emulsion wastewater in mechanical industry.Based on the analysis of the advantages and disadvantages of the existing pretreatment methods for emulsion wastewater and the quality of emulsion wastewater,the possible pretreatment process schemes for emulsion wastewater were proposed.The optimum process scheme was screened by experiments.The improvement scheme of pretreatment facilities was then completed by the optimum process.The main results of this paper are as follows: the optimum conditions for demulsification of emulsion wastewater are that p H is set at 8.0,dosage of polyaluminium chloride is 3 g /(L wastewater),and dosage of polyacrylamide is 1.5mg /(L wastewater).After demulsification,the emulsion wastewater was further treated by distillation separation,activated carbon adsorption and Fenton catalytic oxidation.According to the comparison of the removal effects of chemical oxygen demand(COD)by the three methods,the distillation treatment method was the best.The pretreatment process was finally determined to be physicochemical demulsification and distillation.According to the best technological scheme,they are determined that the three-dimensions and volumes of the main structures and the parameters of the main equipment of facilities.After the treatment of emulsion wastewater by reformed facilities,the concentrations of COD,ammonia nitrogen,total phosphorus and petroleum pollutants of emulsion wastewater are less than 10mg/L,2.57 mg/L,0.01 mg/L and 0.07 mg/L,respectively.All the indexes meet the influent standard of urban comprehensive wastewater treatment plant...